Our remarkable capacity to process information in sound is demonstrated everyday as we make sense of the continuous pattern of variation in the acoustic signals we encounter. The long-term goal of this project is to better understand this ability in normal-hearing adults through controlled measures of their ability to detect and discriminate variation in acoustic patterns made up of tones. There are three key elements of our approach. First, all efforts are linked by a single theoretical framework where the information in the patterns is given precise meaning and listener performance is evaluated relative to a common performance standard. Second, the manner in which different internal factors influence the listener's response is determined from trial-by:trial analyses of the data. Third, specific hypotheses regarding the outcome of experiments are generated based on known nonlinear transformations performed at the auditory periphery and a decision model that has made accurate predictions for the results of many past studies [R.A. Lutfi, J. Acoust. Soc. Am. 94, 748-758 (1993)]. Present aims are to: (1) measure auditory nonlinearity in the discrimination of pure-tone frequency, intensity and duration (2) determine the specific influence of auditory nonlinearity, listener decision weights, and internal noise on the integration of information across frequency and time, and (3) demonstrate successful achievement of aims by maximizing information rate through stimulus design. By advancing our understanding of the normal adult capacity to process information in sound the results may prove key in the development of technologies and rehabilitative strategies that deal more effectively with the impact of dysfunctional hearing on everyday listening.